Nov. 8, 2021 -- If your morning coffee doesn’t taste like it used to, your coffee maker may not be to blame. A careful review of research suggests climate change may be wreaking havoc on the growing conditions needed for a perfect cup of joe.
Coffee, native to Ethiopia, is grown on more than 27 million acres globally, mostly on small farms in more than 50 countries. It fares best in tropical climates with moderate temperatures and rich soil. Ideal conditions for arabica coffee plants include temperatures ranging from 57 to 68 F, annual rainfall between 39 to 106 inches, and an annual dry season that lasts 1 to 3 months.
As these optimal conditions become less common and weather becomes more extreme, we may increasingly taste and smell the difference in our cup, scientists argue in the review, published in Frontiers in Plant Science. They note that changes in the chemical balance of the coffee plant can affect not only smell and taste but also compounds relevant to human health and nutrition.
They based their conclusions on data from 73 published studies that focused on environmental factors and farming practices linked to climate change, as well as adaptations to shifting weather patterns.
Farms at higher altitudes generally produced coffee beans with the best flavor and aroma, the authors found. Conditions that compromise coffee quality include too much heat and light and too little water, which are all are increasingly common thanks to droughts associated with climate change. Coffee also may be susceptible to rising carbon dioxide levels, a byproduct of burning fossil fuels.
Some farming techniques that could ward off these effects include shade structures to limit light exposure and reduce heat on the fields, and the development of climate-resistant coffee plants. The studies included in the review weren’t controlled experiments designed to prove exactly what might protect coffee from climate change. The authors note that more research is needed to explore useful strategies.
In the meantime, an open question is how climate change might affect any health benefits of coffee, which has been linked to a longer lifespan and lower risk of heart disease, certain cancers, type 2 diabetes, and cognitive decline.